Organic Chemistry of Explosives

Cyclobutanes and their derivatives 69

where the two electronegative nitro groups are positionedanti-periplanar to one another.

Trans-1,2-dinitrocyclopropane (2) was found to have a density of 1.59 g/cm^3 , although its

chemical and thermal stability was not investigated.

NO 2

NO 2

NH 2

NH 2 NO 2

NO 2

OMs

OMs

9

10

1. NaH, DMSO


2. DMSO, I 2
   3. Na 2 S 2 O 3 (aq)
   43 % (3 steps)

7 8

O 3 (excess),

silica gel, -78 °C

20–28 %

1. NaN 3 , DMSO


2. PPh 3 , wet THF


3. HCl (aq)


4. KOH, distillation
   85 % (overall)

Figure 2.3

Wade and co-workers^2 used a similar strategy for the synthesis oftrans-1,2-dinitrospiro-

pentane (10), which is prepared in 43 % yield by treating the dianion of 1,1-bis(nitromethyl)-

cyclopropane (9) with iodine in DMSO; the latter prepared by treating the corresponding

diamine (8) with excess ozone while absorbed onto the surface of silica gel.

H

NO 2

NO 2

NO 2

LDA, THF, -80 °C

(^1112)
Figure 2.4
The fused dicyclopropane (12) has been synthesized by treating nitrocyclopropane (11)
with lithium diisopropylamine in THF at low temperature.^3
N 2 O 4 O 2 N NO 2
13 14
Figure 2.5
1,3-Dinitrobicyclo[1.1.1]pentane (14) is the major product from treating [1.1.1]propellane
(13) with dinitrogen tetroxide.^4

2.3 Cyclobutanes and their derivatives

Archibald and co-workers^5 have explored the synthesis of polynitrocyclobutanes and their

derivatives. The synthesis of these compounds via the nucleophilic substitution of cyclobutyl

halides with nitrite anion was ruled out at an early stage because displacement in this system

is too slow for practical use. This is a consequence of the molecular strain in the cyclobutane

ring, which causes carbon atoms to deviate from sp^3 hybridization towards sp^2 character.